Bradykinin B2 Research Articles

Tissue Kallikrein-1 Suppresses Type I Interferon Responses and Reduces Depressive-Like Behavior in the MRL/lpr Lupus-Prone Mouse Model.

Excessive production and response to Type I interferons (IFNs) is a hallmark of systemic lupus erythematosus (SLE). Neuropsychiatric lupus (NPSLE) is a common manifestation of human SLE, with major depression as the most common presentation. Clinical studies have demonstrated that IFNα can cause depressive symptoms. We have shown that the kallikrein-kinin system (KKS) [comprised of kallikreins (Klks) and bradykinins] and angiotensin-converting enzyme inhibitors suppressed Type I IFN responses in dendritic cells from lupus-prone mice and human peripheral blood mononuclear cells. Tissue Klk genes are decreased in patients with lupus, and giving exogenous Klk1 ameliorated kidney pathology in mice. We retro-orbitally administered mouse klk1 gene-carrying adenovirus in the Murphy Roths Large lymphoproliferative (MRL/lpr) lupus-prone mice at early disease onset and analyzed immune responses and depressive-like behavior. Klk1 improved depressive-like behavior, suppressed interferon-responsive genes and neuroinflammation, and reduced plasma IFNα levels and proinflammatory cytokines. Klk1 also reduced IFNAR1 and JAK1 protein expression, important upstream molecules in Type I IFN signaling. Klk1 reduced bradykinin B1 receptor expression, which is known to induce proinflammatory response. Together, these findings suggest that Klk1 may be a potential therapeutic candidate to control IFNα production/responses and other inflammatory responses in SLE and NPSLE.

Targeting CD13/aminopeptidase N as a novel therapeutic approach for scleroderma fibrosis.

Systemic sclerosis (SSc) is an autoimmune multisystem disease with poorly understood pathogenesis and ineffective treatment options. Soluble CD13 (sCD13), generated by cleavage of cell surface CD13 via matrix metalloproteinase 14 (MMP14), signals through the bradykinin receptor B1 (B1R) to elicit pro-inflammatory, pro-arthritic, and pro-angiogenic responses. In this study we explored the anti-fibrotic potential of targeting the sCD13-B1R axis in SSc. The expression of CD13, B1R and MMP14 was examined in SSc skin and explanted dermal fibroblasts. The efficacy of B1R antagonists in the inhibition on fibrosis was determined in vitro and in vivo. Expression of the genes for CD13, B1R and MMP14 was elevated in skin biopsies from patients with diffuse cutaneous (dc)SSc. Notably, single cell analysis of SSc skin biopsies revealed the highest BDKRB1 expression in COL8A1-positive myofibroblasts, a population exclusively seen in SSc. TGF-β induced the expression of BDKRB1 and production of sCD13 by dcSSc skin fibroblasts. Treatment of dcSSc fibroblasts with sCD13 promoted fibrotic gene expression, signaling, cell proliferation, migration, and gel contraction. The profibrotic sCD13 or TGFβ responses were prevented by a B1R antagonist. Mice lacking Cd13 or Bdkrb1 were resistant to bleomycin-induced skin fibrosis and inflammation. Pharmacological B1R inhibition had a comparable antifibrotic effect. These results are the first to demonstrate a key role for sCD13 in SSc skin fibrosis, and suggest that targeting the sCD13-B1R signaling axis is a promising novel therapeutic approach for SSc.

Protein kinase C epsilon contributes to chronic mechanoreflex sensitization in rats with heart failure.

We investigated second-messenger signalling components linked to the stimulation of Gq protein-coupled receptors (e.g. thromboxane A2 and bradykinin B2 receptors) on the sensory endings of thin fibre muscle afferents in the chronic mechanoreflex sensitization in rats with myocardial infarction-induced heart failure with reduced ejection fraction (HF-rEF). We hypothesized that injection of either the inositol 1,4,5-trisphosphate (IP3) receptor antagonist xestospongin C (5µg) or the PKCε translocation inhibitor PKCe141 (45µg) into the arterial supply of the hindlimb would reduce the increase in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) evoked during 30s of 1Hz dynamic hindlimb muscle stretch in decerebrate, unanaesthetized HF-rEF rats but not sham-operated controls (SHAM). Ejection fraction was significantly reduced in HF-rEF (45 (19)%) compared to SHAM (80 (9)%; P<0.001) rats. In HF-rEF rats (n=3M/2F), IP3 receptor blockade had no effect on the peak ΔRSNA (pre: 99 (74)%; post: 133 (79)%; P=0.974) or peak ΔMAP response to stretch (peak ΔMAP: pre: 32 (14) mmHg; post: 36 (21) mmHg; P=0.719). Conversely, in another group of HF-rEF rats (n=4M/3F), the PKCε translocation inhibitor reduced the peak ΔRSNA (pre: 110 (77)%; post: 62 (58)%; P=0.029) and peak ΔMAP response to stretch (pre: 30 (20) mmHg; post: 17 (16) mmHg; P=0.048). In SHAM counterparts, neither drug affected the mechanoreflex responses. Our findings highlight PKCε, but not IP3 receptors, as a significant second-messenger in the chronic mechanoreflex sensitization in HF-rEF which may play a crucial role in the exaggerated sympathetic response to exercise in this patient population. KEY POINTS: Skeletal muscle contraction results in an exaggerated reflex increase in sympathetic nerve activity in heart failure patients with reduced ejection fraction (HF-rEF) compared to healthy individuals, contributing to increased cardiovascular risk and impaired tolerance for mild exercise. The exaggerated reflex sympathetic responses in HF-rEF may be attributed to a chronic sensitization of mechanically sensitive thin fibre muscle afferents mediated, at least in part, by stimulation of Gq protein-coupled thromboxane A2 and bradykinin B2 receptors on muscle afferent sensory endings. The specific Gq protein-linked signalling mechanisms that produce the chronic mechanoreflex sensitization in HF-rEF have not been investigated but may involve inositol 1,4,5-trisphosphate (IP3) receptors and/or protein kinase C epsilon (PKCε). Here we demonstrate that PKCε, but not IP3 receptors, within the sensory endings of thin fibre muscle afferents plays a role in the sensitization of mechanically sensitive thin fibre muscle afferents in rats with HF-rEF.

R-954, a bradykinin B1 receptor antagonist, as a potential therapy in a preclinical endometriosis model

Endometriosis is a gynecological condition characterized by the growth of endometrium-like tissues outside of the uterine cavity. Currently available drugs are efficacious in treating endometriosis-related pain, however it’s not a targeted treatment. The aim of this work is to evaluate the effects of R-954, a bradykinin B1 receptor antagonist, in a murine model of endometriosis. The model was induced in animals through autologous transplantation of part of the uterine horn. After 51 days, it was observed that implants developed into endometriotic lesions. The administration of R-954 or progesterone, for 15 consecutive days, prevented the progression of cyst development, reduced the size and weight of the cysts. Both treatments also reduced cellular infiltrate and production of inflammatory mediators (interleukin-1β, interleukin-6, tumor necrosis factor). However, only R-954 decreased angiogenic factors (VEGF and VEGF receptor). In addition, treatment with the antagonist did not interfere in the females’ estrous cycle, as well as prevented gestational losses (reduction in the number of intermediate resorptions in pregnant females with endometriosis). Data suggested that R-954 has anti-inflammatory and anti-angiogenic effects; does not influence the estrous cycle; and prevents the number of gestational losses suggesting it as a good candidate for endometriosis treatment.

Advent of oral medications for the treatment of hereditary angioedema.

Hereditary angioedema (HAE) is a rare genetic disorder characterized by unpredictable, debilitating episodes of submucosal and/or subcutaneous tissue swelling, which may be life-threatening depending on anatomic location. The two primary management strategies for HAE are ready access to effective on-demand treatment in all patients and the prevention of attacks (short-term prophylaxis [STP] and long-term prophylaxis [LTP]) in appropriate patients. All approved on-demand and most LTP medications require subcutaneous or intravenous administration. Injection-related challenges include trypanophobia (fear of needles), difficulty with self-administration, injection-site reactions (e.g., pain, erythema, bleeding, bruising), and anxiety-all contributing to poor compliance and administration delays. Oral HAE treatments may improve outcomes by reducing treatment barriers. To review oral therapies, approved or in development, for on-demand treatment and/or prevention of HAE attacks. To provide a comprehensive review, data was obtained from publicly available resources through a targeted PubMed literature review and supplemented by information provided on company websites (search cutoff of May 31, 2024). Berotralstat, an oral plasma kallikrein (PKa) inhibitor, is approved for LTP. Sebetralstat, another PKa inhibitor, is the investigational first oral on-demand HAE treatment to complete a phase 3 trial. Deucrictibant, an oral bradykinin B2 receptor antagonist, has completed phase 2 trials for on-demand therapy and LTP. Several other oral PKa inhibitors (ATN249, VE-4666, and VE-4062) are in early development for LTP. Substantial advances have been made in the development of oral treatments for HAE. These treatments have the potential to improve and optimize clinical outcomes, satisfaction, and quality of life among patients with HAE.

Electroacupuncture alleviates diabetes-induced mechanical allodynia and downregulates bradykinin B1 receptor expression in spinal cord dorsal horn.

Diabetic neuropathic pain (DNP) is one of the most prevalent symptoms of diabetes. The alteration of proteins in the spinal cord dorsal horn (SCDH) plays a significant role in the genesis and the development of DNP. Our previous study has shown electroacupuncture could effectively relieve DNP. However, the potential mechanism inducing DNP's genesis and development remains unclear and needs further research. This study established DNP model rats by intraperitoneally injecting a single high-dose streptozotocin; 2 Hz electroacupuncture was used to stimulate Zusanli (ST36) and Kunlun (BL60) of DNP rats daily from day 15 to day 21 after streptozotocin injection. Behavioral assay, quantitative PCR, immunofluorescence staining, and western blotting were used to study the analgesic mechanism of electroacupuncture. The bradykinin B1 receptor (B1R) mRNA, nuclear factor-κB p65 (p65), substance P, and calcitonin gene-related peptide (CGRP) protein expression were significantly enhanced in SCDH of DNP rats. The paw withdrawal threshold was increased while body weight and fasting blood glucose did not change in DNP rats after the electroacupuncture treatment. The expression of B1R, p65, substance P, and CGRP in SCDH of DNP rats was also inhibited after the electroacupuncture treatment. This work suggests that the potential mechanisms inducing the allodynia of DNP rats were possibly related to the increased expression of B1R, p65, substance P, and CGRP in SCDH. Downregulating B1R, p65, substance P, and CGRP expression levels in SCDH may achieve the analgesic effect of 2 Hz electroacupuncture treatment.

Blood Vessels

Abstract: One of the primary target tissues for inflammatory and allergy mediators is the blood vessel, and cytokines have a variety of impacts on it. We describe the usefulness of isolated blood vessels immersed in organ baths as a valuable source of pharmacological data. Contractility assays provide strong potency and selectivity data on agonists, partial agonists, and competitive or noncompetitive antagonists; however, their use in the bioassay of vasoactive drugs is gradually being replaced by more advanced analytical techniques. The human umbilical vein, for instance, has been widely utilized to identify bradykinin B2 receptor ligands. Isolated segments of vascular tissue are highly reactive living tissues, particularly in terms of regulating gene products associated with inflammation (e.g., kinin B1 receptor). The venule’s extremely thin walls have the potential to burst due to their high volume. Venules allow blood to move into larger veins. Both veins and arteries have three layers in their walls. On the other hand, venous pressure is modest. Veins are less elastic and have thin walls, allowing them to maintain a high blood circulation rate. The venous system’s high capacitance enables it to store a significant amount of blood at comparatively low pressures, containing around 75% of the circulating blood at any given time. The veins’ one-way valves permit blood to move forward toward the heart through muscle contractions.

Preconditioning by Moderate-Intensity Exercise Prevents Gentamicin-Induced Acute Kidney Injury.

A strict correlation among proximal tubule epithelial cell dysfunction, proteinuria, and modulation of the Renin-Angiotensin System and Kalikrein-Kinin System are crucial factors in the pathogenesis of Acute Kidney Injury (AKI). In this study, we investigated the potential protective effect of preconditioning by moderate-intensity aerobic exercise on gentamicin-induced AKI. Male Wistar rats were submitted to a moderate-intensity treadmill exercise protocol for 8 weeks, and then injected with 80 mg/kg/day s.c. gentamicin for 5 consecutive days. Four groups were generated: 1) NT+SAL (control); 2) NT+AKI (non-trained with AKI); 3) T+SAL (trained); and 4) T+AKI (trained with AKI). The NT+AKI group presented: 1) impairment in glomerular function parameters; 2) increased fractional excretion of Na + , K + , and water; 4) proteinuria and increased urinary γ-glutamyl transferase activity (a marker of tubular injury) accompanied by acute tubular necrosis; 5) an increased renal angiotensin-converting enzyme and bradykinin B1 receptor mRNA expression. Interestingly, the preconditioning by moderate-intensity aerobic exercise attenuated all alterations observed in gentamicin-induced AKI (T+AKI group). Taken together, our results show that the preconditioning by moderate-intensity aerobic exercise ameliorates the development of gentamicin-induced AKI. Our findings help to expand the current knowledge regarding the effect of physical exercise on kidneys during physiological and pathological conditions.

Assessment of Radiolabelled Derivatives of R954 for Detection of Bradykinin B1 Receptor in Cancer Cells: Studies on Glioblastoma Xenografts in Mice.

Bradykinin B1 receptor (B1R) has garnered attention as a cancer therapeutic and diagnostic target. Several reports on radiolabelled derivatives of B1R antagonists have shown favourable properties as imaging agents in cells highly expressing hB1R following transfection. In the present study, we assessed whether radiolabelled probes can detect B1R endogenously expressed in cancer cells. To this end, we evaluated 111In-labelled derivatives of a B1R antagonist ([111In]In-DOTA-Ahx-R954) using glioblastoma cell lines (U87MG and U251MG) with different B1R expression levels. Cellular uptake studies showed that the specific accumulation of [111In]In-DOTA-Ahx-R954 in U87MG was higher than that in U251MG, which correlated with B1R expression levels. Tissue distribution in U87MG-bearing mice revealed approximately 2-fold higher radioactivity in tumours than in the muscle in the contralateral leg. The specific accumulation of [111In]In-DOTA-Ahx-R954 in the tumour was demonstrated by the reduction in the tumour-to-plasma ratios in nonlabelled R954-treated mice. Moreover, ex vivo autoradiographic images revealed that the intratumoural distribution of [111In]In-DOTA-Ahx-R954 correlated with the localisation of B1R-expressing glioblastoma cells. In conclusion, we demonstrated that [111In]In-DOTA-Ahx-R954 radioactivity correlated with B1R expression in glioblastoma cells, indicating that radiolabelled derivatives of the B1R antagonist could serve as promising tools for elucidating the involvement of B1R in cancer.

B2R-Targeting Radiotracer for PET/MR Imaging of Hepatocellular Carcinoma and Guiding Anti-B2R Therapy.

The bradykinin B2 receptor (B2R) is overexpressed in a wide variety of tumors and is a well-defined target for tumor imaging and therapy. The hybrid positron emission tomography/magnetic resonance imaging (PET/MRI) scanner is considered a noninvasive and advanced instrument for precise tumor imaging. In this work, we developed a novel B2R-targeting radiotracer, 68Ga-DOTA-icatibant, for quantifying B2R expression. 68Ga-DOTA-icatibant showed high stability, fast clearance and specific binding to B2R. PET/MR imaging revealed excellent tumor accumulation, and the uptake in tumors could be blocked by DOTA-icatibant. Icatibant-mediated anti-B2R therapy downregulated B2R expression in tumor cells and inhibited the growth of HepG2 tumors, and the decrease in tumor uptake was monitored by timely PET/MR imaging. Hematoxylin and eosin (H&E) and immunohistochemical staining results further demonstrated that the efficacy of anti-B2R could be accurately monitored with the developed PET/MR imaging radiotracer. 68Ga-DOTA-icatibant can be utilized to noninvasively determine B2R expression and dynamically and sensitively monitor the efficacy of anti-B2R therapy.

Factor XII and prekallikrein promote microvascular inflammation and psoriasis in mice.

Psoriasis is an autoimmune inflammatory skin disease, featuring microvascular abnormalities and elevated levels of bradykinin. Contact activation of Factor XII can initiate the plasma kallikrein-kinin cascade, producing inflammation and angioedema. The role of Factor XII in psoriasis is unknown. The effects of deficiency of Factor XII or its enzymatic substrate, prekallikrein, were examined in the imiquimod-induced mouse model of psoriasis. Skin microcirculation was assessed using intravital confocal microscopy and laser Doppler flowmeter. A novel antibody blocking Factor XII activation was evaluated for psoriasis prevention. Expression of Factor XII was markedly up-regulated in human and mouse psoriatic skin. Genetic deletion of Factor XII or prekallikrein, attenuated imiquimod-induced psoriatic lesions in mice. Psoriatic induction increased skin microvascular blood perfusion, causing vasodilation, hyperpermeability and angiogenesis. It also promoted neutrophil-vascular interaction, inflammatory cytokine release and enhanced Factor XII / prekallikrein enzymatic activity with elevated bradykinin. Factor XII or prekallikrein deficiency ameliorated these microvascular abnormalities and abolished bradykinin increase. Antagonism of bradykinin B2 receptors reproduced the microvascular protection of Factor XII / prekallikrein deficiency, attenuated psoriatic lesions, and prevented protection by Factor XII / prekallikrein deficiency against psoriasis. Furthermore, treatment of mice with Factor XII antibody alleviated experimentally induced psoriasis and suppressed microvascular inflammation. Activation of Factor XII promoted psoriasis via prekallikrein-dependent formation of bradykinin, which critically mediated psoriatic microvascular inflammation. Inhibition of contact activation represents a novel therapeutic strategy for psoriasis.

Deletion of AT1a Receptors Selectively in Renomedullary Interstitial Cells Attenuates Basal, Angiotensin II-, or Vasopressin-induced Vasoactive Factors' mRNA Expression in The Mouse Kidney Medulla

We recently shown that deletion of the vasoactive peptide angiotensin II (Ang II) AT1a receptors selectively in renomedullary interstitial cells (RMICs) of the kidney medulla significantly lowered basal blood pressure and impaired urine concentration in mice. However, the underlying signaling mechanisms involved remains poorly understood. In the present study, AT1a receptors were selectively deleted in the RMICs of the mouse kidney medulla using tamoxifen-inducible Tenascin-C-CreER2/Agtr1af/f approach. Three groups of adult male wild-type (WT) and RMIC- Agtr1a−/− mice (n=6-10) were pretreated with or without tamoxifen (150 mg/kg, i.p., for 5 days) before Ang II was infused to induce Ang II-dependent hypertension (~0.75 mg/kg/day, i.p., for 2 weeks). Systolic, diastolic, and mean arterial blood pressure and urine osmolality were determined before and after Ang II treatment. At the end of the experiment, the kidneys were harvested, and the inner and outer medulla were dissected out for the measurement of the mRNA expression of key vasoactive factors that are associated with the regulation of blood pressure and urine concentration using digital droplet PCR. Deletion of AT1a receptors in RMICs significantly decreased AT1a receptor mRNA expression by 41% (WT: 554 ± 49 vs. RMIC- Agtr1a−/−: 327 ± 10 copies/ng RNA; P&lt;0.01) and bradykinin B2 receptor mRNA expression by 52% (WT: 10.10 ± 0.75 vs. RMIC- Agtr1a−/−: 4.90 ± 0.56 copies/ng RNA; P&lt;0.01), without altering the expression of endothelin ETB (WT: 466 ± 21 vs. RMIC- Agtr1a−/−: 393 ± 24 copies/ng RNA; n.s.) and vasopressin V2 receptor mRNAs in the kidney medulla (WT: 580 ± 60 vs. RMIC- Agtr1a−/−: 586 ± 61 copies/ng RNA; n.s.). Deletion of AT1a receptors in RMICs also significantly decreased the expression of eNOS (WT: 87.0 ± 3.0 vs. RMIC- Agtr1a−/−: 61.2 ± 2.8 copies/ng RNA; P&lt;0.01) and aquaporin 2 (AQP2) mRNAs (WT: 12463 ± 2015 vs. RMIC- Agtr1a−/−: 6613 ± 692 copies/ng RNA; P&lt;0.01). Interestingly, deletion of AT1a receptors in RMICs did not alter the mRNA expression of cyclooxygenase-2 (COX-2, n.s.), prostaglandin E2 (PGE2, n.s.), epithelial sodium channel (ENaC, n.s.) or prorenin receptors (PRR, n.s.) in the kidney medulla. In response to Ang II infusion, deletion of AT1a receptors in RMICs significantly attenuated Ang II-induced expression of bradykinin B2 receptors, COX-2, eNOS, and AQP2 mRNAs ( P&lt;0.01), respectively. Furthermore, deletion of AT1a receptors in RMICs also significantly attenuated vasopressin-induced bradykinin B2 receptor, eNOS, and AQP2 mRNA expression in the kidney medulla ( P&lt;0.01). We concluded that AT1a receptors in RMICs in the kidney medulla play an important role in maintaining physiological blood pressure homeostasis and urine concentration process likely via AT1a receptor/bradykinin B2 receptor/eNOS/AQP2-mediated signaling pathways. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

DELETION OF BRADYKININ TYPE 2 RECEPTORS SELECTIVELY IN THE RENOMEDULLARY INTERSTITIAL CELLS OF THE KIDNEY MEDULLA ATTENUATES ANGIOTENSIN II-INDUCED HYPERTENSION IN MICE

Objective: The present study tested the hypothesis that deletion of vasoactive peptide bradykinin B2 receptors selectively in the renomemdullary interstitial cells (RMICs) of the kidney medulla attenuates angiotensin II-induced hypertension in mice. Design and method: To test the hypothesis, we employed inducible Tenascin-C-CreER2 and bradykinin B2 receptor-floxed recombination approach to generate a novel mouse model with deletion of B2 receptors selectively in the RMICs of the kidney medulla (RMIC-B2R-/-). Basal blood pressure and urine osmolality and their responses to angiotensin II (Ang II, ∼500 μg/kg/day, i.p., for 2 weeks) were determined in adult male wildtype (WT) and RMIC-B2R-/- mice (n=10 per group), respectively. Results: Mice with deletion of B2 receptors selectively in RMICs of the kidney medulla developed normally without structural abnormalities in the kidney medulla. However, basal telemetry systolic, diastolic, and mean arterial blood pressure were significantly lower in RMIC-B2R-/- than WT mice (WT: 123 ± 3 mmHg vs. RMIC-B2R-/-: 106 ± 3 mmHg, P&lt;0.01). The hypotensive phenotype in RMIC-B2R-/- mice was associated with significant decreases in 24 h urine output (WT: 1.86 ± 0.15 mL/24 h vs. RMIC-B2R-/-: 1.09 ± 0.15 mL/24 h, P&lt;0.05) and urine osmolality (WT: 1893 ± 441 mOsm/Kg H2O vs. RMIC-B2R-/-: 1311 ± 78 mOsm/Kg H2O, P&lt;0.01). In response to Ang II infusion (∼0.5 mg/kg/day, i.p., for 2 weeks), systolic blood pressure increased to 166 ± 6 mmHg in WT mice (P&lt;0.01 vs. Basal), but it increased only to 139 ± 5 mmHg in RMIC-B2R-/- mice (P&lt;0.01 vs. WT). By comparison, infusion of DDAVP (1-deamino-8-D-arginine vasopressin, ∼0.5 mg/kg/day, i.p., for 2 weeks) did not significantly alter blood pressure in WT and RMIC-B2R-/- mice (n.s.). However, infusion of Ang II for 2 weeks significantly increased urine osmolality in WT mice (P&lt;0.01), and restored urine osmolality in RMIC-B2R-/- mice to the WT basal level (1995 ± 315 mOsm/Kg H2O, P&lt;0.01). Conclusions: In conclusion, the present study demonstrates for the 1st time that bradykinin B2 receptors in the RMICs of the kidney medulla plays an important role in maintaining basal blood pressure and urine osmolality homeostasis and the development of Ang II-induced hypertension.

Cellular localization and seasonal variation of GnRH and Bradykinin in the ovary of Heteropneustes fossilis (Bloch.) during its reproductive cycle

The present study investigates the distribution and dynamics of gonadotropin-releasing hormone I (GnRH I) and bradykinin in the air-breathing catfish, Heteropneustes fossilis, in relation to the reproductive cycle. Changes in bradykinin, bradykinin B2-receptor, and ovarian GnRH I regulation were demonstrated during the reproductive cycle. The localization of GnRH I, bradykinin, and their respective receptors in the ovaries was investigated by immunohistochemistry, while their levels were quantified by slot/western blot followed by densitometry. GnRH I and its receptor were mainly localized in the cytoplasm of oocytes during the early previtellogenic phase. However, as the follicles grew larger, immunoreactivity was observed in the granulosa and theca cells of the late previtellogenic follicles. The ovaries showed significantly higher expression of GnRH I protein and its receptor during the early to mid-previtellogenic phase, suggesting their involvement in follicular development. Bradykinin and bradykinin B2-receptor showed a distribution pattern similar to that of GnRH I and its receptor. This study further suggested the possibility that bradykinin regulates GnRH I synthesis in the ovary. Thus, we show that the catfish ovary has a GnRH-bradykinin system and plays a role in follicular development and oocyte maturation in H. fossilis.

Bradykinin attenuates endothelial-mesenchymal transition following cardiac ischemia-reperfusion injury

AimsEndothelial-mesenchymal transition (EndMT) is a crucial pathological process contributing to cardiac fibrosis. Bradykinin has been found to protect the heart against fibrosis. Whether bradykinin regulates EndMT has not been determined. Materials and methodsRats were subjected to ligation of the left anterior descending coronary artery for 1 h and subsequent reperfusion to induce cardiac ischemia-reperfusion (IR) injury. Bradykinin (0.5 μg/h) was infused by an osmotic pump implanted subcutaneously at the onset of reperfusion. Fourteen days later, the functional, histological, and molecular analyses were performed to investigate the changes in cardiac fibrosis and EndMT. Human coronary artery endothelial cells were utilized to determine the molecular mechanisms in vitro. ResultsBradykinin treatment improved cardiac function and decreased fibrosis following cardiac IR injury, accompanied by ameliorated EndMT and increased nitric oxide (NO) production. In vitro experiments found that bradykinin mitigated transforming growth factor β1 (TGFβ1)-induced EndMT. Significantly, the bradykinin B2 receptor antagonist or endothelial nitric oxide synthase inhibitor abolished the effects of bradykinin on EndMT inhibition, indicating that the bradykinin B2 receptor and NO might mediate the effects of bradykinin on EndMT inhibition. ConclusionBradykinin plays an essential role in the process of cardiac fibrosis. Bradykinin preserves the cellular signature of endothelial cells, preventing them from EndMT following cardiac IR injury, possibly mediated by bradykinin B2 receptor activation and NO production.

New Light on Plants and Their Chemical Compounds Used in Polish Folk Medicine to Treat Urinary Diseases.

This review contains the results of Polish (Central Europe) ethnomedical studies that describe the treatment of urinary tract diseases with wild and cultivated plants. The study includes only the plants that are used to treat the urinary tract, excluding prostate diseases. A review of the literature was carried out to verify the pharmacological use of the plants mentioned in the interviews. Based on this, the study reviews the pharmacological activities of all the recorded species and indicates their most important chemical compounds. Fifty-three species (belonging to 30 families) were selected for the study. The Compositae (eight species), Rosaceae (six species), and Apiaceae (six species) are the most common families used in the treatment of urinary diseases in Polish folk medicine. Both in vitro and in vivo studies have confirmed that many of these plant species have beneficial properties, such as diuretic, antihyperuricemic, antimicrobial, and anti-inflammatory activity, or the prevention of urinary stone formation. These effects are exerted through different mechanisms, for example, through the activation of bradykinin B2 receptors, inhibition of xanthine oxidase, or inhibition of Na+-K+ pump. Many plants used in folk medicine are rich in phytochemicals with proven effectiveness against urinary tract diseases, such as rutin, arbutin, or triterpene saponins.

Maximakinin reversed H2O2 induced oxidative damage in rat cardiac H9c2 cells through AMPK/Akt and AMPK/ERK1/2 signaling pathways

Maximakinin (MK), a homolog of bradykinin (BK), is extracted from skin venom of the Chinese toad Bombina maxima. Although MK has a good antihypertensive effect, its effect on myocardial cells is unclear. This study investigates the protective effect of MK on hydrogen peroxide (H2O2)-induced oxidative damage in rat cardiac H9c2 cells and explores its mechanism of action. A 3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl Tetrazolium Bromide (MTT) assay was selected to detect the effect of MK on H9c2 cell viability, while flow cytometry was used to investigate the influence of MK and H2O2 on intracellular reactive oxygen species (ROS) levels. Protein expression changes were detected by western blot. In addition, specific protein inhibitors were applied to confirm the induction of ROS-related signaling pathways by MK. MTT assay results show that MK significantly reversed H2O2-induced cell growth inhibition. Flow cytometry Dichlorodihydrofluorescein diacetate (DCFH-DA) staining shows that MK significantly reversed H2O2-induced increases in intracellular ROS production in H9c2 cells. Moreover, the addition of specific protein inhibitors suggests that MK reverses H2O2-induced oxidative damage by activating AMP-activated protein kinase (AMPK)/protein kinase B (Akt) and AMPK/extracellular-regulated kinase 1/2 (ERK1/2) pathways. Finally, an inhibitor of bradykinin B2 receptors (B2Rs), HOE-140, was applied to investigate potential targets of MK in H9c2 cells. HOE-140 significantly blocked induction of AMPK/Akt and AMPK/ERK1/2 pathways by MK, suggesting a potentially important role for B2Rs in MK reversing H2O2-induced oxidative damage. Above all, MK protects against oxidative damage by inhibiting H2O2-induced ROS production in H9c2 cells. The protective mechanism of MK may be achieved by activation of B2Rs to activate downstream AMPK/Akt and AMPK/ERK1/2 pathways.

Deucrictibant for angioedema due to acquired C1-inhibitor deficiency: A randomized-controlled trial

BackgroundAngioedema due to acquired C1-inhibitor deficiency is a very rare but serious disease, with an estimated prevalence of 1 per 500,000 persons. There are no approved therapies to treat or prevent angioedema swellings in patients with this condition. Deucrictibant is a specific, orally bioavailable, competitive antagonist of the bradykinin B2 receptor currently under investigation for hereditary angioedema. ObjectiveTo assess the efficacy and safety of deucrictibant as acute and prophylactic treatment for angioedema due to acquired C1-inhibitor deficiency. MethodsA two-part, randomized, double-blind, placebo-controlled crossover study was conducted. In Part 1, four consecutive angioedema attacks were treated with three doses of deucrictibant (10 mg, 20 mg, and 30 mg) or placebo. In Part 2, deucricibant 20 mg or placebo was administered bidaily for two treatment periods of eight weeks. ResultsThree patients were enrolled of which one completed both study parts and two completed only Part 2. In Part 1, a reduction in attack severity was observed in the three attacks treated with deucrictibant as opposed to an increase in severity of the attack treated with placebo. In Part 2, the individual mean monthly attack rates were 2.0, 0.6 and 1.0 during the placebo period and 0.0 across all patients during treatment with deucrictibant. There were no severe adverse events, and one self-limiting treatment-emergent adverse event (abdominal pain). ConclusionsDeucrictibant has the potential to effectively and safely treat and prevent angioedema attacks due to acquired C1-inhibitor deficiency.

Analgesic and Psychotropic Effects of a New Bradykinin Antagonist.

A bradykinin B1 receptors antagonist PAV-0056, an 1,4-benzodiazepin-2-one derivative, intragastrically administrated to mice at doses of 0.1 and 1 mg/kg causes analgesia in the "formalin test" not inferior to that of diclofenac sodium (10 mg/kg) and tramadol (20 mg/kg). PAV-0056 at doses of 0.1 and 10 mg/kg has no anxiolytic and central muscle relaxant effects in mice and does not damage the gastric mucosa in rats. Based on the results of the conditioned place preference test, PAV-0056 also does not induce addiction in mice.

Plasma microRNAs as biomarkers in hereditary angioedema

BackgroundHereditary angioedema (HAE) is an autosomal dominant disease with variable expression. In some families with identical genetic abnormalities, the expression can range from several attacks per month to no attacks at all. It is hypothesized that post-transcriptional gene regulation accounts for the variable expression of the disease. ObjectiveTo identify candidate microRNAs (miRNAs) that could play a role in HAE by determining whether miRNAs are differentially expressed in patients with HAE vs non-HAE individuals and whether expression profiles are tracked with severity. MethodsThis study compared serum miRNA expression in patients with HAE vs non-HAE using RNA sequencing. Associations between miRNA expression and HAE severity were assessed in patients with mild disease (<6 attacks a year) vs severe disease (>1 attack per month). The functions of candidate miRNAs were analyzed using in silico methods. ResultsThere were robust miRNA expression differences between patients with HAE and non-HAE controls. A cluster analysis identified subgroups of patients with HAE having unique miRNA profiles that tracked with frequency of attacks. Two miRNAs, miR-99b-5p and miR-127-3p, were differentially expressed between mild and severe HAE (adjusted P < .05). In silico analysis revealed a function of differentially expressed miRNAs in regulation of C1 esterase inhibitor, kininogen, the bradykinin B2 receptor, and adherens junction function. ConclusionCandidate microRNAs were identified that could distinguish patients with and without HAE and may be used to identify phenotypes of HAE.